Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Add support for the Forecast Convergence Score to MET. #49

Open
JohnHalleyGotway opened this issue Sep 24, 2019 · 2 comments
Open

Add support for the Forecast Convergence Score to MET. #49

JohnHalleyGotway opened this issue Sep 24, 2019 · 2 comments
Assignees
Labels
requestor: NOAA/MDL NOAA Meteorological Development Laboratory type: new feature Make it do something new

Comments

@JohnHalleyGotway
Copy link
Contributor

This is a request from NOAA/MDL:
https://sats.nws.noaa.gov/~verification/mos/help.html

Currently applied to point locations, not gridded analyses. But it could be applied to gridded analyses.

This is related to forecast consistency and should be included as one of the statistics.

Forecast Convergence Score (FCS)

The Ruth-Glahn Forecast Convergence Score (FCS) is an index that measures the number of large swings in forecasts made over a series of forecast cycles for forecasts valid at the same time. Assume there are N forecasts made over a number of days. With each subsequent forecast cycle, the forecast projection decreases until the valid time of the forecast is reached. The FCS is defined as follows:

(T1 + T2)
FCS = -----------------
(T3 + T4)

where T1 = the number of forecasts that changed insignificantly (less than the threshold) from the previous forecast Fi-1 OR moved closer to the next forecast Fi+1, where i varies from 2 to N. When i=N, the observation is used as the next forecast Fi+1.

|FN - F1|
T2 = -------------------
threshold

T3 = N-1

|Fi - Fi-1|
(from i = 2 to N)
T4 = ----------------------
threshold

The T1 and T3 terms account for the actual and possible number of swings, respectively.

The T2 and T4 terms account for the magnitude of the swings.

A significance threshold specifies the minimum change necessary to count as a swing.

The FCS ranges from 0.0 (many large swings with no convergence toward the observation) to 1.0 (no large swings with the forecasts converging toward the observation.)

A "case" is an unbroken series of forecasts for the entire 7 days, all valid at the same time, ending with the observation at the valid time. Thus, the number of cases is generally smaller than the number of cases for other statistics. Any gap in the forecasts or observations causes the case to be eliminated from the sample.

@JohnHalleyGotway
Copy link
Contributor Author

Need to define where this functionality should be implemented: MET, METviewer, METcalcpy/METplotpy

@JohnHalleyGotway JohnHalleyGotway transferred this issue from dtcenter/MET Nov 5, 2020
@JohnHalleyGotway
Copy link
Contributor Author

This was originally defined in MET but belongs in METcalcpy instead. This is related to forecast consistency.

@bikegeek bikegeek added the requestor: NOAA/MDL NOAA Meteorological Development Laboratory label Dec 16, 2020
@bikegeek bikegeek added this to the METcalcpy-1.0 milestone Dec 16, 2020
@bikegeek bikegeek added priority: high High Priority type: new feature Make it do something new labels Dec 16, 2020
@bikegeek bikegeek removed the priority: high High Priority label Feb 10, 2021
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
Labels
requestor: NOAA/MDL NOAA Meteorological Development Laboratory type: new feature Make it do something new
Projects
None yet
Development

No branches or pull requests

4 participants